Electron multipliers are useful tools for various applications, including the detection of photons, electrons, ions and heavy particles. Such detectors are utilized in various spectroscopic techniques, including Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and electron energy loss spectroscopy. Further, electron multipliers may be utilized for detection of secondary and back-scattered electrons in scanning electron microscopes, focused ion-beam tools, or e-beam lithography tools.
Typical electron multipliers are either channel type (e.g., multipliers that are tubular in nature) or flat plate type, including two flat plates that are usually parallel to each other. Channel electron multipliers can suppress ion feedback by shaping the channel (e.g., curved or spiraled) so that the travel distance of feedback ions is short. However, because of their geometry, channel electron multipliers are not suitable for the detection of incoming charged or energetic neutral particles or photon beams with a cross sectional profile that is not round. Parallel plate electron multipliers can be shaped to accommodate beam profiles that are not round. However, due to the fact that they are usually constructed with flat parallel plates they are prone to ion feedback problems.
There is a need in the art for a parallel plate electron multiplier that suppresses ion feedback.